Conventionally, as this type of back-contact-type solar cell and a manufacturing method thereof, there has been known a following back-contact-type solar cell and a manufacturing method thereof as described below. That is, a silicon oxide film is formed on a back surface side of the silicon substrate as a mask for impurity diffusion, a predetermined portion of the silicon oxide film is removed by etching and, thereafter, an n-type diffusion layer (n+ region) is formed on the predetermined portion. Then, the silicon oxide film which is used as the mask for impurity diffusion is removed and, thereafter, a p-type diffusion layer (p+ region) is formed. On the p-type diffusion layer, a back surface electrode which is brought into contact with the n-type diffusion layer in a dotted manner and an electrode which is brought into contact with the P-type diffusion layer in a dotted manner are respectively formed. Both diffusion layers and both electrodes are formed in a comb-teeth shape such that the diffusion layers and the electrodes have oppositely-facing portions thereof merged with each other on a back surface side of the silicon substrate (see Patent Reference 1, for example).
Further, there has also been known a back-contact-type solar cell in which a linear n+-type diffusion layer and a linear p+-type diffusion layer are alternately formed on a back surface of a semiconductor substrate at equal pitches (see Patent Reference 2, for example).
Patent Reference 1: Japanese Patent Laid-open 2002-164556 (page 2 to 3, FIG. 1 and FIG. 4)
Patent Reference 2: Japanese Patent Laid-open 2004-71828 (page 2, FIG. 1(a))